Jean pierre serve



(No Model.)

J. P. SERVE.

TUBULAR BOILER.

No. 398,003. I Patented Feb. 19, 1889.

Fig. 1

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JEAN PIERRE SERVE, OF GIVORS, FRANCE.

TUBULAR BOILER.

SPECIFICATION-fanning part of Letters Patent No. 398,003, dated February 19, 1889. Application filed December 4, 1888. Serial No. 292,610- (NO m del-l To all whom it may concern.-

Be it known that I, JEAN PIERRE SERVE, a citizen of the Republic of France, and a resident of Givors, in the said Republic, have invented certain new and useful Improvements in Tubular Boilers, of which the following is a specification.

The chief object of this invention is to neutralize in tubular boilers the disadvantageous effects due to the expansion of the tubes, particularly when the tubes and the boiler-shell are made of metals having adifferent coeffi-.

cient of expansion. Thus, for instance, in the boilers of locomotives as usually constructed, the iron tube-plate of the smoke-box being much more rigid than the tube-plate of the fire-box, which is of copper, the difference of expansion betweenthc body of the boiler and the cluster of tubes produces a considerable strain 011 the fire-box tube-plate, which rapidly disintegrates the metal and seriously damages the fire-box and the connections of the latter with the tubes.

My invention consists partly in relieving the tube-plate of the fire-box from the strain due to the lengthening of the tubes by allowing this strain to be taken up by a rigid resistance-plate or its equivalent placed behind the fire-box and partly in allowing the tubeplate of the smoke-box to yield slightly to the action of the said elongation bymeans of the improved construction of the said plate or of its connections with the boiler.

Referring to the accompanying drawings, Figure 1 is a vertical longitudinal section of a locomotive-boiler containing my improvements. Fig. 2 is asimilar vertical section showing a variation in the method of attaching the tube-plate to the end of the boiler nearer the smoke-box. Figs. 3, 4, and 5 are details hereinafter referred to.

As shown in Figs. 1 and 3, a plate, I), preferably of iron, with great resisting power, is placed behind the tube-plate a of the fire-box. Through this iron plate the tubes 0 freely pass. Each tube is provided with a projecting piece or collar, d, the edge of which meets the said plate I), which is itself solidly fixed in the boiler. The plate I) may rest against the inner flange of the exterior wall of the fire-box or may be held in any other suitable manner. It will be understood that under these conditions the plate I) will offer an absolute resistance to the strains which would otherwise be exerted against the tube-plate a by the expansion of the tubes, and that this strain will now act in the opposite directionnamely, against the tube-plate e of the smokebox. In order that plate 6 may yield to a certain extent under this strain, a certain amount of elasticity is imparted to the hinder part of the boiler, as follows:

--. In the arrangement shown in Fig. l the tube-plate e is somewhat larger in diameter than the body of the boiler f, and its outer edge is bent backward and downward to allow it to be fastened to the said boiler f and to produce the required elasticity in the plate. In the modification shown in Fig. 2 the tubeplate is flat, and is connected with the body of the boiler f by means of an arched or corrugated flange, g, which is sufliciently elastic for the purpose above mentioned. If preferred, the tube-plate c may be attached to the boiler f by an internal stead of an external one. In any of these forms the slight outward displacement of the plate 6 is assisted by the steam-pressure in the boiler, which is produced at the same time as the heating of the tubes.

It will be understood that the interior pressure of the boiler will drive back the plate e to a degree depending chiefly on its diameter and on the resisting force of the attachingflange; but these two elements maybe so calculated as to render the displacement of the said plate proportional to the expansion of the tubes. Thus the amount of recoil of the tube-plate e, determined by the'pressure of steam upon it, being equal to the corresponding expansion of the tubes, this expansion will not exert any great strain on the abutment-plate b.

In the arrangement shown in Fig. l the endwise movement of the tubes 0 in one direction is restrained by a resisting-plate, b, which is made in one piece. The upper edge of this plate does not project much abovethe upper edge of the tubes 0, and so it allows a free passage for the water must be understood that for this plate I) several parallel pieces may be substituted, the

arched flange in- 7 and steam; but it roe said pieces being arranged in different vertical planes. These pieces may be of variable thickness to support a certain number of rows of tubes, the plates themselves being supported at the back by horizontal or vertical bars, rods, or suitable stays placed endwise, which stays will otter a considerable resistance and furnish a firm support to the par tial abutment-plates. This method is particularly applicable when the system is applied to boilers of a large diameter. The projections (1 on the tubes may be formed either by a ring placed. on the tube (see Fig. 4) or by means of a welded joint, leaving a projecting edge at the, point of junction, as seen in Fig.

Itis evident that with this system the holes in the plate 6 must be of sufficient diameter to allow of the passage of the projections cl of the tubes, and that the said tubes must be a slightly-elastic circumferential collar united slightly enlarged at this end, as seen in Figs. 1 and 2 of the drawings.

I claim as my invention- 1. In a multit-ubular boiler, the combination, with the fire-box tube-plate and the boiler-tud es, of a rigid abutment plate or plates, bxprerced with holes for the passage of the tubes, and of a series of ferrules or projections, (I, fixed to the said tubes and each adapted to abut against the inner face of the said abutment plate or plates,

whereby the strain of the longitudinal expansion of the tubes on the'firebox tube-plate is transferred to the rigid abutment plate or plates, substantially as described.

2. In a multitubular boiler, a series of boiler-tubes furnished with rings or projections abutting against. a fixed abutment plate or plates, 1), at the fire-box end of the boiler, in combination with a smoke-box tube-plate of a different diameter from that. of the body of the boiler and fixed to the said body by curved or arched flanges arranged around its inner or outer circumference and capable of permitting a certain amount of elasticity in the said tube-plate, substantially as described.

3. In a mnltitubular boiler, the combination, with the fixed abutment plate or plates b and the tubes 0, having projections abutting against the same at the firebox end, of aboiler-shell provided at the smoke-box end with with the smoke-box tube-plate, substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JEAN PIERRE SERVE.

\Vitnesses:

ALFRED BOZIRE, GUILLAUNIE Ponrrnnn. 

